Question

Two angles of a triangle are ${50}^{\circ }$​ and ${70}^{\circ }$​. The third angle is:

• A. ${50}^{\circ }$
• B. ${70}^{\circ }$
• C. ${60}^{\circ }$
• D. ${120}^{\circ }$

Answer 1

The correct option is C

${60}^{\circ }$

The sum of all the angles of a triangle is ${180}^{\circ }$​.

Therefore,
$\text{Third angle}={180}^{\circ }-({50}^{\circ }+{70}^{\circ })={180}^{\circ }-\left({120}^{\circ }\right)={60}^{\circ }$​